If you’re eager to get your hands on OS X Yosemite, Apple has released its upcoming operating system as a free beta for the first million downloaders.

Though Yosemite has been available to registered members of the Mac Developer Program since June, Apple has for the first time in its history decided to give customers a taste of the upcoming software in. The public beta should be stable enough for most regular users, but issues are bound to arise and some third-party programs may not yet work.

To download OS X Yosemite you will need a valid Apple ID, and your Mac should already be running Mavericks 10.9.3. If you’re not familiar with the installation process, be sure to read through this guide for all the steps.

There are three ways you can install Yosemite on your Mac: on a separate partition (which Apple suggests), to an external hard drive (not recommended) or by replacing the current Mavericks OS (also not recommended). The following describes how to create a partition on your Mac’s hard drive, so you can test Yosemite without harming your Mac.

Create A Partition

Before you download and install Yosemite, you need to partition your Mac.

1. Launch Disk Utility and select your startup drive, then select Partition. You should have enough free space on your Mac to create at least a 20GB partition for Yosemite.

2. Click the plus “+” button at the bottom of the partition layout to create another partition. Select it input the amount space you want (Apple recommends 8GB minimum, but you’ll need 20GB to test it properly). Under Format, select the Mac OS Extended (Journal) from the drop-down list. Name your partition “Yosemite Test” or similar so you know which one to delete when the time comes.

3. Click Apply to start the partition process. Make sure the pop-up dialogue box says that no partitions will be erased, especially your main startup drive.

Download & Install The Beta Installer

To download Yosemite, you will need to join the OS X Beta Program using your Apple ID. After signing in and reading over the guide, scroll to the bottom of the page and click the blue redemption code button. Once you’ve confirmed and read the information, the Mac App Store will launch then you can sign in and begin downloading the Yosemite Installer application, which is a little over 5GB.

The Yosemite Installer is downloaded to your Applications folder. When installer opens up, select the Yosemite partition you created, and click the install button. If you want to try Yosemite on other Macs, make sure you take a copy of the installer before you run it.

To install the beta, simply run the installer you just downloaded. When prompted, carefully select the partition you created earlier, as per the screenshot above. Follow the prompts, until eventually your Mac restarts to complete the installation.

Don’t Use iCloud Drive

After the installer restarts your Mac and installs Yosemite, you will be presented with a series of questions similar to the ones you got when installing Mavericks.

You should avoid upgrading to iCloud Drive if you rely on devices using older versions of OS X or iOS, due to incompatibilities between the new iCloud Drive and older software. You can enable iCloud Drive under System Preferences > iCloud after the official release.

To get back to Mavericks while in Yosemite, launch System Preferences > Startup Disk. Select your main drive and click restart. You can also hold down the option (alt) key at startup and choose your partition from there.

When it comes to installing Yosemite proper, upgrade from within your Mavericks installation and then you can use Disk Utility to delete the test partition you created for the beta.

Irresponsible would be a better description than useless. You won’t find anyone at Apple who agrees with your statement that Yosemite beta is for most regular users. You won’t find anyone who has made their living supporting “most regular users" for more than a year who agrees that Yosemite beta is for those users.

"The public beta should be stable enough for most regular users, but issues are bound to arise and some third-party programs may not yet work.”

This is not enough of a warning. For "most regular users," installing Yosemite beta is a stupid thing to do. You will lose all sorts of support options from Apple and from third party developers. For the risk you take, there is little or nothing to gain in terms of being able to “make use of” your Mac better. Wait until Apple's official release of Yosemite - unless you are very curious, have a lot of free time, and don't rely on your Mac to do meaningful work.

This article is about as helpful to the average user as an article entitled "Fix the holes in your underwear with a stapler.”

Bruce, that's cold. But I guess I'm saying that if you're willing to lose support for some third-party apps, replacing Mavericks with Yosemite may be okay. I did so on my MacBook Air because I didn't have enough space to create a partition drive. As result, I've only lost support for one application, which thankfully I don't use much anyway on the laptop. Granted, I do much of my work on my iMac.

I don't think most readers of this article will be replacing Mavericks with Yosemite, especially since the step-by-step instructions talk about installing it on a partition drive. But anyway, sorry you find the article useless.

My reaserches give me the same results, and I thouhght it won't let mi install Yosemetie.
But, the installation took me 15 minutes and I can test beta of the newest mac OS, while having Mountain Lion as my primary OS. Thanks for the help mate :)

It's to big of a risk to replace my OS since I use my MBP for work purposes. I've installed it on my main (and only) hard drive, just on a separate partition. I have some artefacts when resizing finder windows but other then that it works fine. This weekend i will configure some work tools on Yosemite, and I'll try to work on it, but I will live my Mountain Lion OS till a stable Yosemite comes out.

I'm a long time Mac user, downloaded the beta about a week ago on my IMac and have found it to be great. I like the style and ease of use and have had very few crashes etc. Safari also seems to work well.

You must be one of those readers who don't read articles and just go based on a headline and past information that you know. Tis a shame. Thanks for the article Bakari and informing us of how to install the beta!